Monday, February 14, 2011

Guest Post: the D'Backs On The Mound

Well, it's one of the greatest days of the year. The smell of freshly cut Kentucky Bluegrass is in the air and the familiar sounds of bat on ball, ball on leather, and Ozzie Guillen yelling at somebody can be heard once again. Pitchers and catchers for 17 teams have already reported, and by Friday every team will have opened camp and begun their 2011 Spring Training in Arizona or Florida. It's been a long winter, folks, but baseball is finally back.

In other exciting news, we've got a guest poster today. Julian Tucker, a dear friend of mine, put together a few pieces and asked whether I would post them here, to which I agreed. I'll try to throw up a post of my own by the end of the week, as we're pretty close to finishing up Perfect Pickups for the last few non-playoff teams from last season.

Anyway, Julian, take it away:

Few things in baseball were as bad as the Arizona Diamondbacks’ pitching staff last season. As a fan of the San Francisco Giants, who also play in the NL West and an avid sports highlight show watcher, I can tell you that it seemed like everyday that the Diamondbacks’ bullpen would blow a lead and end up losing the game. Looking back, we can see that this pitching staff was historically bad, and all signs indicate that it has nowhere to go but up. In 2010, the starting rotation for the Diamondbacks was awful. They were middle of the road in terms of innings pitched, strikeouts per nine innings and walks per nine innings. However, they allowed an incredible 1.34 home runs per nine innings, which was worst in the majors by far. Arizona’s starting staff also induced the lowest percentage of groundballs in the league (40.7%) while allowing high percentages of line drives (19.2%) and fly balls (40.1%). They also posted a terrible 4.62 FIP, third worst in the league. What all of this says to me is that the Diamondback starters were incredibly adept at inducing fly balls, and an inordinate amount of those fly balls ended up in the seats for home runs. A common explanation for this was that Chase Field, Arizona’s home ballpark, was especially hitter-friendly early in the season due to the desert climate. OK, I buy that one a little bit. But, it doesn’t change the fact that in 2011, Arizona’s starters are going to have to get better at inducing more groundballs and less fly balls, especially early on.

Arizona’s bullpen exceeded the starters in terms of awfulness by a large margin. D-back relievers combined to save only 35 games, lose 32, strike out a mere 6.79 batters per nine innings while walking 4.59 and allowing 1.27 HR/9. They also allowed an unbelievable 12 percent of all fly balls to leave the yard. That means that basically one out of every eight fly balls hit off of an Arizona reliever went into the stands. From the stats, it is easy to see why they were so bad. They were not good at striking out batters, giving the opposing team lots of chances to make contact with pitches. Arizona’s bullpen handed out free passes like there was no tomorrow. Its BABIP of .310 was extremely unlucky, and should rebound to a more normal number in 2011. What is interesting is that the bullpen was actually pretty good at inducing ground balls instead of fly balls. With a ground ball percentage of 44.1% and a fly ball rate of 37.2%, the D-backs were about league average or better in those two categories. The problem was that so many of their fly balls went for home runs, as noted earlier. Whether this was truly due to the “Chase Field effect” or just bad luck, regression to the mean next year is practically inevitable.
Looking at some statistics related to win probability, the true scope of the damage caused by the bullpen is clear. A league worst -8.37 WPA and a -3.4 Clutch score show that not only did Arizona’s relief corps cost the team over eight wins during the season, it also faltered when it mattered the most in high-leverage situations.

After this nightmare in 2010, what has Arizona done to shore up its bullpen? Not a whole lot, surprisingly. The club signed J.J. Putz to a two-year deal to be the team’s closer, but other than that, Micah Owings appears to be the team’s biggest possible add for its relief corps this offseason. The team has traded for and signed several pitchers to be starters, including Armando Galarraga, Zach Duke and Aaron Heilman, but it seems like Kevin Towers is content to sign a good closer, a veteran relief arm, some fringe starters and hope for a rebound back to respectability in 2011. For that to happen, it would be helpful for Arizona pitchers to strike more hitters out, walk less and hopefully reduce its number of fly balls.

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This is meant to be an MLB blog, incorporating a little bit of math, a little bit of fandom, and a whole lot of baseball. I welcome your comments, questions, and concerns. If there's something you'd like to see, I want to hear it! Post on the blog by clicking the comment link at the bottom of the post or shoot me an email: dougwac@umich.edu

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